Michael Blessenohl:
> I'm sorry, I'll try not to use my smartphone again to answer mails from
> this list.
>
> I ment using a remote machine as client to connect to the postfix server
> as opposed to connect to the machine itself. I don't know why it does
> matter, but apparently it does. Using the hostname, IP or localhost
> makes no difference at all. That's the same for me.
You may want to look into the following parameter.
allow_untrusted_routing (default: no)
Forward mail with sender-specified routing (user[@%!]remote[@%!]site)
from untrusted clients to destinations matching $relay_domains.
By default, this feature is turned off. This closes a nasty
open relay loophole where a backup MX host can be tricked
into forwarding junk mail to a primary MX host which then spams
it out to the world.
Postfix flags an address with @ in the local-part as an address
with sender-specified routing, regardless of whether it is quoted.
Postfix will not relay such an address unless the above safety
feature is turned off.
Wietse
